The ability to ambulate in the community is of critical importance for carrying out daily activities;yet 50% of hip fracture patients who walked independently before a fracture require assistance to walk 10 feet a year later, and many of those that are able to walk without assistance move so slowly that they are no longer able to walk a distance considered adequate for community ambulation. The proposed study will evaluate the ability of a high intensity, 16-week, multi-component exercise program beginning two months post-fracture to improve patients'ability to walk a community ambulation distance at 4 months post-initiation of the program. Forty exercise sessions will be provided in patients'place of residence under the direct supervision of physical therapists;exercises will be targeted to improve endurance, balance, muscle strength, and functional task performance. This two group randomized clinical trial will determine if a 16-week training program can improve patients'ability to walk a community ambulation distance of 300 meters in six minutes at 4 months following randomization. Three clinical sites (University of Maryland Baltimore;Arcadia University;University of Connecticut Health Center) will recruit a total of 300 community dwelling hip fracture patients (aged 65+) following hospitalization, and randomly assign them to a 16-week high intensity, supervised, home delivered multi-component exercise program or a control intervention consisting of stretching and range of motion exercises, and low level transcutaneous electrical stimulation. Patients will be randomized after standard post- acute rehabilitative care ends (2 months post-fracture). Patients in both groups will receive supplemental vitamin D3, calcium, a multivitamin and nutritional counseling to promote weight stability and adequate nutrient intake. The primary endpoint is the ability to walk 300 meters in 6 minutes four months post randomization. Other endpoints include precursors (i.e., endurance, balance, muscle performance, and lower extremity function) and selected underlying mechanisms (i.e., intra-muscular fat, quadriceps volume, circulating inflammatory cytokines, and VO2 peak) to community ambulation. Cost effectiveness also will be evaluated. The study is designed to detect at least a 20 percentage point difference between the exercise and control groups in the primary outcome with 90 percent power (alpha=. 05) in an intention to treat analysis. Results will lead to a better understanding of the dynamics of innovative post hip fracture physical therapy. Implications of study findings will relate directly to hip fracture patients'ability to ambulate independently in the community and the cost-effectiveness of the proposed intervention. PUBLIC HEALTH RELEVANCE: More than 325,000 hip fractures occur annually in the US, with associated health care costs estimated at $14-20 billion. The goal of current clinical practice is independent, safe household ambulation, at 2-3 months post surgery, yet hip fracture-acquired dependency persists well beyond three months. This study will evaluate a 16-week multi-component exercise program provided to patients in their homes to determine if it is effective in improving the ability to walk independently in the community (i.e., community ambulation).